2001 Golf Biodiesel oil analysis

[tadc]

Mobil Truck & SUV 5w40, 10k miles on sample, 110k on engine.

Iron-40
Chromium-2
Lead-19
Copper-5
Tin-0
Aluminum-4
Nickel-1
Silver-0
Silicon-4
Boron-53
Sodium-19
Potassium-5
Magnesium-96
Calicum-2202
Phosphorus-748
Zinc-952
Molybdenum-77
Fuel-A
Water [email protected] cST
TBN-5.87
soot-.1
Ox-20
Nitration-11

Thoughts? Predictive Maintenance Services says that the additive package changed drastically, although I thought I was still using Delvac1/Mobil T&SUV and the Viscosity has dropped nearly to the bottom of the 30weight range. This is mostly running B99... I thought BD was supposed to make your oil *thicker*, if anything? Can anybody explain what's going on here? Is the Pb or Fe number something to be concerned about?

I'm fairly certain this oil was the "old" T&SUV, not the new stuff, but I could be wrong.

Is it possible that oil contamination with BD would cause the drop in viscosity without testing postive for "fuel", aka petrodiesel?

 

[tdimaniac]

wow that is unusually thin. i bet you put in the 5w30, the delvac1/mobil1 5w40 in my car was 13.2 at 10k miles (with some biodiesel). you should post this at tdiclub for more feedback imho.

 

[tadc]

Posted, but getting little in the way of response about the analysis...

 

[1040 WreckerMan]

I can't speak to what affect the B99 has as I have not seen much data about it's affect on oil. I'll have some idea after I send in my current sample which has a lot of B99 use.

I wouldn't be worried about the iron number really, it typically increases with time in the crankcase. Since the soot is low I would think that blowby, and hence biodiesel contamination in oil, is also going to be low. Silicon is low so the air filter and related components are doing their job well. The only thing that looks out of place to me is the "high" lead. That could just be due to the low viscosity, but I'm not sure what these engines like for viscosity so take it with a grain of salt. There is also some potassium and sodium which are components in coolant. However they could also be part of the add pack, check the VOA section and see if that can be confirmed (have a receipt or empty bottle from your oil change to confirm what version of oil you used?). Do you have any other UOA's on this engine? It is hard to tell much without several UOA's to establish a trend. I'm certainly no expert at UOA interpretation, so I hope that helped some.

 

[TooSlick]

This is clearly the SAE 5w-30/SUV, ie it's basically the Mobil 1, 5w-30. You can clearly tell by looking at the additive chemistry, which contains MoDTC and only 100 ppm of magnesium, vs about 400 ppm for Delvac 1. The viscosity of 10.6 Cst is also a give away, which is mid-range 30wt.

This oil is too thin for this application, hence the high bearing wear. You'd typically see low single digit bearing wear with a 5w-40 or 10w-40.

On another topic, your biodiesel has traces of K and Na from it's previous life as french fry oil....

TS

 

[Pablo]

There is some error here. I doubt highly the oil thinned this much. Do you have a container or some of this virgin oil left?

I have a bad habit of always keeping a container of the virgin oils/fluids in my cars.

 

[1040 WreckerMan]

Sodium and potassium are not harmful in small amounts. If these elements were being introduced as a coolant leak then you would want to try and find the source of the leak. Never thought about the fuel being the source, but it makes sense. I would run an oil that better suites the engine to try and get the lead down to a lower number.

 

[tadc]

Thanks for the comments. Can anybody comment as to whether the K and Na are harmful in any way or just indicative of the recycled fuel used?

I've gone with Rotella Synthetic this time around as I am reluctant to use an oil that I can't source locally(and I didn't want to buy a case of Delvac).

My last UOA is from 60k miles ago, so not much help there.